NUCLEO-H745 + ST-Link Utility = Can not connect to target

[ksamy.1]

We tried our custom board that has STM32H745XI through ST-link V2 with updated firmware. Initially in boot mode the board connects and we were able to read flash. Then after some time the SWD connection is lost.

It is not even able to debug the application. We measured the power supply on CRO and also connectivity with the MCU. We connected SWDIO,SWCLK and ground pins with the stlink.

[ksamy.1]

After removing level translator that is used in nucleo board (in swdio and swo lines) and keeping the on-board MCU supply jumpers off, Now we are able to connect the STM32H745XI custom board in boot mode and erase flash successfully. However, we are not able to load firmware or debug in normal boot mode. Any suggestion on this.

[Tesla DeLorean]

Need to cycle power after first code load.

Check option byte settings.

I​ would probably start by getting a UART running so I could report on internal state. The work on getting HSE and PLL up.

[Uwe Bonnes]

Quoting error messages is usefull. Testing the setup with other tools (OpenOCD, pyocd, bl*ckm*g*c, etc) is usefull too.

[ksamy.1]

how to connect stlink v3 of nucleo-h745zi to external stm32H745 custom board?

[ksamy.1]

The voltage at Vcap is 1.005V and SDC voltge is 1.2V

[ksamy.1]

The CN5 connector on Nucleo-H745ZI is SWD port. I have disconnected the on-board MCU(STM32H745ZI) and connected my custom board at this port so that it can communicate with SLink, but i receive message STM32 target not found even though correct voltages measured at VCAP(1.005V) and 1.2V at SDC

[ksamy.1]

Finally resolved the problem: if we want to connect the nucleo-H745ZI stlinkV3 to external custom board (STM32H745XI) using CN5, then we need to remove few components that disconnects vdd, smps and ldo supply from main mcu U14(144pins).

Thanks everyone who replied to my queries.